DynakitParts wrote: Looks nice... Does that emblem represent the star of Ishtar? Kevin

Nah ... more like the Star of Yamaha ... three road ninjas bearing gifts from afar were said to have followed it into a participating dealership ... and then I bought it on closeout. I'll probably lose it eventually. especially if I come across a nice Star of Ishtar!

The tape is rated to 600F ... just how hot do these transformers run?? My only concern was heat dissipation, but I don't expect it'd be any worse than a standard paint job. I like the way you can just rub it into the surface. Long as you're careful putting it on, any little ripples or crinkles can be flattened nicely. Even if the glue were to fail, it's a tight fit, and I'd expect the foil to stay in place.

Stuff's real handy for all sorts of little projects around the house. Someday I expect I'll even use it on ductwork.

PS ... those stacks aren't all that easy to clean, are they? I played around with sandpaper, buffing pads, wool, etc and finally ended up using a safety razor blade edge on. That did a nice job of cleaning the tops of the plates, and just scraping the corner of the blade in the grooves made for a nice effect. I may end up peeling the tape and sealing the bare metal with a rust preventative. Either way should get some nice reflections off the tubes.

The metal tape isn't about insulation - it's more of an infiltration kinda thing. It's actually quite thin - that's what allows it to mold itself to the surface as well as it does. I wouldn't think it'd hold any more heat than a coat of paint, and might even help reflect heat from the tubes.

Or not ... one way to find out.

Maybe get one more item to add to the great steaming pile of myth and myth-stakes regarding transformer painting. I've seen everything from pitched battles about EM proof paint to eddy currents caused by sealing the stacks and changing the "flavor" of the sound.

I'm still thinking of peeling the foil off and just leave em naked though. Cleaned up quite nice without the bling. Any suggestions on rustproofing the stack? I was thinking something like this ...

sKiZo wrote:The metal tape isn't about insulation - it's more of an infiltration kinda thing. It's actually quite thin - that's what allows it to mold itself to the surface as well as it does. I wouldn't think it'd hold any more heat than a coat of paint, and might even help reflect heat from the tubes.

The adhesive on the back of the tape is the insulation, not the metal. You'd be better off building a heat "dam" with the metal tape forming a wall between the tubes and the transformers.

Just to prove I had a fallback position ... presto chango, and we're naked again ...

Don't think I had to worry about the tape falling off. Getting it started was a PITA, but once I got an edge lifted, careful and slow got it all off fairly easily. If anything, it did a nice job of deep cleaning the bare metal - lotsa black stuff stuck to the tape on the way off. I do have my doubts as to whether it would have come off as easy and clean if it had a chance to bake on for a while though.

Kinda like the looks as is - the caps even have a real decent finish from the factory. Like anything else, once it gets buried behind a bunch of other stuff, it'll look even better.

Then again, we got three more days of rain coming, so plenty of time to play.

The adhesive on the back of the tape is the insulation, not the metal.

I think I see where maybe some of the confusion is coming in. There's two types of metal duct tape. One has a fairly thick insulating layer, one doesn't. The adhesive layer on this stuff isn't much thicker than what you'd get with scotch packing tape. As you can see, it's paper thin once you remove the backing. It doesn't insulate the ductwork - just makes it airtight.

sKiZo wrote:The adhesive on the back of the tape is the insulation, not the metal.

I think I see where maybe some of the confusion is coming in. There's two types of metal duct tape. One has a fairly thick insulating layer, one doesn't. The adhesive layer on this stuff isn't much thicker than what you'd get with scotch packing tape. As you can see, it's paper thin once you remove the backing. It doesn't insulate the ductwork - just makes it airtight.

No confusion here; I meant the actual gluey stuff on the back of the metal facing, not any insulation that may have been included. The gluey stuff is not a good thermal conductor. It's not a great thermal insulator either, but it's still retaining some of the trafo's heat. For all we know the metal facing on the inside of the tape may have been reflecting some of the heat back into the trafo too, as it wasn't making direct metal-to-metal contact with the laminations. I think you were wise to remove it. I installed finned heat sinks on my Dyna ST-70 power transformer once. They were ugly as sin and helped only a little. I finally found an aftermarket, or later version of the transformer that was noticeably taller than the original. It ran a good bit cooler.

The tape will significantly insulate the transformer by reducing radiated heat. Silvered surfaces have a very low emissivity. If you have a black surface and a silvered surface at the same temperature, the black surface will radiate more heat (if you put your hand nearby it will feel warmer). That is why they make shiny silver coffee pots and shiny silver duct tape.

If you put silvered tape on the transformer, the silver surface will insulate the transformer and increase its operating temperature. The thin glue layer would have a minor effect. The black painted transformer will run coolest. Keeping the top black will help a lot, since most of the heat will radiate upwards. It would actually be good to silver the side pointing to the hot tubes; since the tubes are hotter than the transformer, the silvered sides would insulate the transformer from getting heated by the tubes. However, I've been too many years out of school to remember how to calculate the temperature differences. A guess would be in the range of 20-40 degrees.